Prosopagnosia (from the Greek for 'face' prosopon, and 'ignorance' agnosia) is the clinical name for the condition of impaired face recognition (Bodamer 1947). This condition has become a central focus for research on face perception, and an important test case for the question of the modularity and structure of the visual system more generally. While a large amount of research has investigated the question of whether the visual recognition deficits of prosopagnosic individuals are selective for faces relative to other objects, there has been little study of prosopagnosics' perceptual abilities other than recognition. Yet deficits in perceptual abilities other than recognition could nonetheless cause impairments in recognition for faces. The proposed research seeks to investigate this possibility by testing three hypotheses. The first hypothesis is that prosopagnosic individuals have perceptual deficits in spatial or color vision. The second is that prosopagnosia results from deficits in form perception, and the third is that it results from deficits in texture perception. These hypotheses will be tested using rigorous psychophysics with a group of developmental prosopagnosic individuals. [unreadable] [unreadable] [unreadable]